The determination of the presence or extent of diseased tissue is important in a range of procedures in medicine and biology. For example, the assessment of malignant tissue is important for the treatment of cancer. A biopsy needle is inserted into the tissue in question to obtain a sample of the tissue such that it can be examined for cancerous cells. An exemplary conventional biopsy needle has a hollow compartment near the tip of the needle to receive the tissue sample, and a cutting blade to cut the tissue sample that is located within the compartment from surrounding tissue. Some biopsy needles may also apply suction to the tissue to pull the tissue sample into the compartment, as is often done in brain biopsies.
A number of problems exist in needle biopsy procedures. For example, it is important to position the biopsy needle to obtain the optimal tissue sample. Specifically, when extracting a tissue sample from cancerous tissue, it is important to obtain the sample from an area containing malignant cells rather than fat or necrotic cells. Additionally, it is important to avoid damaging other physiological structures such as blood vessels.